2004 ISUZU TF SERIES spark plugs

6E-380 3.5L ENGINE DRIVEABILITY AND EMISSIONS
SPARK PLUGS

Removal Procedure
1. Remove spark plugs.

Inspection Procedure
The spark plug affects entire engine performance and
therefore its inspection is very important.
 Check electrode and insulator for presence o
f
cracks, and replace if any.
 Check electrode for wear, and replace if necessary.
 Check gasket for damage, and replace if necessary.
 Measure insulation resistance with an ohmmeter,
and replace if faulty.
 Adjust spark plug gap to 1.0 mm (0.04 in)

1.1 mm
(0.043 in).
 Check fuel and electrical systems if spark plug is
extremely dirty.
 Use spark plugs having low heat value (hot type
plug) if fuel and electrical systems are normal.
 Use spark plugs having high heat value (cold type
plug) if insulator and electrode are extremely
burned.
Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and
insulator of spark plug reduces the engine performance.
Possible causes:
 Too rich mixture
 Presence of oil in combustion chamber
 Incorrectly adjusted spark plug gap
Burning Electrodes
This fault is characterized by scorched or heavily
oxidized electrode or blistered insulator nose.
Possible causes:
 Too lean mixture
 Improper heat value

Measuring Insulation Resistance
 Measure insulation resistance using a 500 volt
megaohm meter.
 Replace spark plugs if measured value is out o
f
standard.
Insulation resistance: 50 M
  or more




011RS010
Cleaning Spark Plugs
 Clean spark plugs with a spark plug cleaner.
 Raise the ground electrode to an angle of 45 to 60
degrees. If electrode is wet, dry it before cleaning.

After spark plug is thoroughly cleaned, check
insulator for presence of cracks.
 Clean threads and metal body with a wire brush.
 File the electrode tip if electrode is extremely worn.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-381
 Bend the ground electrode to adjust the spark plug
gap.




011RS011

Installation Procedure
1. Spark plugs
 Tighten spark plugs to the specified torque.
Torque: 18 N




m (1.8 kg




m/13 lb ft)

ENGINE DIAGNOSIS (C24SE) 6-3
3.Trouble in Fuel System
Condition Possible cause Correction
Starting motor turns over and
spark occurs but engine does not
start. Fuel tank empty Fill
Water in fuel system Clean
Fuel filter clogged Replace filter
Fuel pipe clogged Clean or replace
Fuel pump defective Replace
Fuel pump circuit open Correct or replace
Evaporative Emission Control
system circuit clogged Correct or replace
Multiport Fuel Injection System
faulty Refer to "Electronic Fuel Injection"
section
4.Engine Lacks Compression
Condition Possible cause Correction
Engine lacks compression Spark plug loosely fitted or spark
plug gasket defective Tighten to specified torque or
replace gasket
Spark plug wire incorrect Connect properly or replace
Valve timing incorrect Adjust
Cylinder head gasket defective Replace gasket
Valve incorrectly seated Lap valve
Valve stem seized Replace valve and valve guide
Valve spring weakened Replace
Cylinder or piston rings worn Overhaul engine
Piston ring seized Overhaul engine.

Engine Compression Test Procedure
1. Start and run the engine until the engine
reaches normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and
fuse box. 6. Engage the starter and check that the cranking
speed is approximately 300 rpm.
7. Install cylinder compression gauge into spark
plug hole.
8. With the throttle valve opened fully, keep the
starter engaged until the compression gauge
needle reaches the maximum level. Note the
reading.
9. Repeat the test with each cylinder.
The pressure difference between the individual
cylinders should not exceed 100kPa (14.5 psi).

ENGINE DIAGNOSIS (C24SE) 6-5
Rough Engine Running
Condition Possible cause Correction
Engine misfires regularly Ignition coil layer shorted Replace
Spark plugs fouling Clean or install hotter type plug
Spark plug(s) insulator nose
leaking Replace
Spark plug wire incorrect Connect properly or replace
Fuel injector(s) defective Replace
Engine control module faulty Replace
Engine knocks regularly Spark plugs running too hot Install colder type spark plugs
Powertrain control module faulty Replace
Engine lacks power Spark plugs fouled Clean
Spark plug wire incorrect Connect properly or replace
Fuel injectors defective Replace
Manifold Absolute Pressure
(MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defective Correct or replace
Engine Coolant Temperature
Sensor or Engine Coolant
Temperature Sensor circuit
defective Correct or replace
Engine Control Module faulty Replace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defective Correct or replace
Throttle Position Sensor or
Throttle Position Sensor circuit
defective Correct or replace
Knock Sensor or Knock Sensor
circuits defective Correct or replace
Knock Sensor Module or Knock
Sensor Module circuits defective Correct or replace

ENGINE DIAGNOSIS (C24SE) 6-7
Engine Lacks Power
Condition Possible cause Correction
Trouble in fuel system Fuel Pressure Control Valve not
working normally Replace
Fuel injector clogged Clean or replace
Fuel pipe clogged Clean
Fuel filter clogged or fouled Replace
Fuel pump drive circuit not
working normally Correct or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative
Emission Control System circuit Clean or replace
Water in fuel system Clean
Inferior quality fuel in fuel system Use fuel of specified octane rating
Engine Control Module supplied
poor voltage Correct circuit
Throttle Position Sensor cable
disconnected or broken Correct or replace
Throttle Position Sensor defective Replace
Manifold Absolute Pressure
Sensor not working normally Replace
Intake Air Temperature sensor not
working normally Replace
Engine Coolant Temperature
Sensor circuit open or shorted Correct or replace
Engine Coolant Temperature
Sensor defective Replace
Engine Control Module defective Replace
Trouble in intake or exhaust
system Air Cleaner Filter clogged Replace filter element
Air duct kicked or flattened Correct or replace
Ignition failure
- Refer to Hard Start
Troubleshooting Guide
Heat range of spark plug
inadequate Install spark plugs of adequate
heat range
Electronic Ignition System with
module Replace

6-10 ENGINE DIAGNOSIS (C24SE)
Troubleshooting Procedure

Condition Possible cause Correction
Piston pin noise
(Piston makes noise each time it
goes up and down) Piston pin or piston pin hole worn Replace piston, piston pin and
connecting rod assy

Troubleshooting Procedure
The slapping sound stops when spark plug on bad
cylinder is shorted out.

Condition Possible cause Correction
Timing belt noise Timing belt tension is incorrect Replace pusher or adjust the
tension pulley or replace timing
belt
Tensioner bearing defective Replace
Timing belt defective Replace
Timing wheels defective Replace
Timing belt comes in contact with
timing cover Replace timing belt and timing
cover
Valve noise Valve and valve guide seized Replace valve and valve guide
Valve spring broken Replace
Valve seat off-positioned Correct
Crankshaft noise Crankshaft end play excessive
(noise occurs when clutch is
engaged) Replace thrust bearing
Engine knocking Preignition due to use of spark
plugs of inadequate heat range Install Spark Plugs of adequate
heat range
Fuel too low in octane rating Replace fuel
Wide Open Throttle enrichment
system failure Refer to Section 6E
Selection of transmission gear
incorrect Caution operator or incorrect gear
selection
Engine overheating Refer to "Engine Lacks Power"
Others Water pump defective Replace
V-belt slipping Adjust tension of V-belt or replace
V-belt

ENGINE MECHANICAL (C24SE) 6A-13
Valve System C24SE
Actuation Type Direct-acting Inverted Bucked Tappet
Valve Clearance Adjustment Hydraulic
Valve Rotor Type None
Inlet-Valve Material Chromium Alloyed Steel
-Seat Insert Material Sintered Iron
Exhaust-Valve Material Head: Cr-Mn-Ni Alloyed Shaft: Cr-Si Alloyed &Cr plated
-Seat Insert Material Sintered Iron
Valve Spring Material GME 06 100-C1
Valve Guide Material QS 13 MR 00
Valve Seal Type Lip

Water Pump C24SE
Type Centrifugal
Drive-Material &Type HNBR Toothed-belt
Bearing Type Double Row Ball
Shaft Seal Type Mechanical Ceramic

Thermostat-Coolant C24SE
Type Bypass

Oil Pump & Filter C24SE
Type Gear Pump
Location Front of Engine
Drive Direct Crankshaft Driven
Filter Type Full Flow with Bypass for blocked filter

Oil & Oil Reservoir C24SE
Reservoir-Description & Location 1-piece below Engine
Reservoir Material Aluminum Alloy (pressure cast)
Replacement Oil Fill Volume
-With Filter change 4.25liters
-Without Filter change 4.00liters
Recommended Oil-Run-in 10W/30SG
-Service (above-18C) 10W/40SG
-Service (below-18C) 5W/30SG
Oil Classification API&CCMC

Ignition Components C24SE
Spark Plugs Conventional
Type Electronic Spark Control
No. of Coils &Type 2 Solid State
Coil Location Engine-mounted
Ignition Lead Type Inductive (hi-resistance)

ENGINE MECHANICAL (C24SE) 6A-37


Hydraulic Valve Lifters, Replace
Removal
1. Remove the spark plug connectors and spark plugs.
2. Remove the camshaft housing cover.


Removal
3. Turn the crankshaft at fastening bolt of toothed belt drive
gear in the direction of the engine rotation until the cam
of hydraulic valve lifter being replaced stands vertically.


Removal
4. Apply 5-8840-0457-0 to the camshaft housing, valve
spring cap and tension valve spring.


Removal
5. Remove the cam follower from camshaft housing.
Note thrust pieces.
6. Remove hydraulic valve lifter from camshaft housing.



Camshaft Housing, Replace
Removal
Cylinder head-see operation “Cylinder Head. Remove and
Install”.